title: Physiological variation of segmented OCT retinal layer thicknesses is short-lasting.
abstract: The application of spectral domain optical coherence tomography as a surrogate for neurodegeneration in a range of neurological disorders demands better understanding of the physiological variation of retinal layer thicknesses, which may mask any value of this emerging outcome measure. A prospective study compared retinal layer thicknesses between control subjects (n = 15) and runners (n = 27) participating in a 10-km charity run. Three scans were performed using an eye-tracking function (EBF) and automated scan registration for optimal precision at (1) baseline, (2) directly after the run, and (3) following a rehydration period. Retinal layer segmentation was performed with suppression of axial retinal vessel signal artifacts. Following the run, there was an increase in the relative retinal nerve fibre layer (p = 0.018), the combined inner plexiform/ganglion cell layer (p = 0.038), and the outer nuclear layer (p = 0.018) in runners compared to controls. The initial increase of thickness in the outer nuclear layer of runners (p < 0.0001) was likely related to (noncompliant) rehydration during exercise. Following a period of rest and rehydration, the difference in thickness change for all retinal layers, except the retinal nerve fibre layer (RNFL) (p < 0.05), disappeared between the two groups. There is a quantifiable change in the axial thickness of retinal layersthat which can be explained by an increase in the cellular volume. This effect may potentially be caused by H2O volume shifts.
authors.affiliation: Department of Neurology, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
authors.forename: Lisanne
authors.initials: L
authors.lastname: Balk
authors.forename: Markus
authors.initials: M
authors.lastname: Mayer
authors.forename: Bernard M J
authors.initials: BM
authors.lastname: Uitdehaag
authors.forename: Axel
authors.initials: A
authors.lastname: Petzold
mesh_terms: D000328:Adult; D048429:Cell Size; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis; D012160:Retina / Q000033:anatomy & histology*; D012420:Running / Q000502:physiology; D041623:Tomography, Optical Coherence